Such linear movements in mechanical handling systems are as a rule created through the use of the circular or flat guides. The disadvantages of these systems are substantially the following:
(a) The necessary stiffness in the extended condition often does not exist. This is true in particular for systems in which the gripping mechanism is arranged at the free end of a piston rod (German GM No. 79 10 366).
(b) In the retracted condition, considerable space is required for the component parts which approximately equals the space considered as the range toward the desired target (German GM No. 80 16 572).
(c) A speed reduction prior to reaching the end positions requires additional and expensive control technology.
(d) The moving toward desired targets, which lie outside of a straight line or even in the free space therearound, is often not possible (German OS No. 31 34 784) or requires additional axes (directions of movement) (German OS No. 29 30 006).
(e) A freely changeable characteristic or the ability to adjust to changed manufacturing sequences is almost impossible, in particular when the hand system is substantially integrated into the machine (German OS No. 29 30 006).
Starting out from these findings, the basic purpose of the invention is to provide a handling mechanism which conserves space to as little space as possible separately from the machine tool, which in spite of small dimensions has the necessary stiffness and which without any additional expense reduces the speed of movement of the gripping mechanism prior to reaching the end positions. In addition, it is possible to move to desired targets which lie outside of a straight line.
This purpose is attained by providing a mechanical hand mechanism which can be utilized in situations where the reach is initially adjusted to the respective case and occupies in the initial position only a comparatively small space. The coupling of the hinged arms to the common joint head results in a high degree of stiffness in the extended condition, so that heavy workpieces can also be handled. The end positions are controlled with a high degree of exactness with the aforesaid speed reduction which can be achieved through the inventive arrangement of the joints and arms, which especially is needed during the feeding of machine tools. Single and multiple gripping systems can be arranged on the joint head, and their position stiffness is achieved with a sliding joint parallelogram. The necessary drive power is small, since only the rolling friction in the joints is to be overcome. A further advantage which must be mentioned is the simple construction which is inexpensive to manufacture.
It is a further purpose of the invention to move the gripping mechanism in a rectilinear direction of movement or to one or several desired targets outside of a straight line. An individual desired target next to a straight line can also be reached when the swivel arms and/or the hinged arms are of different lengths.
The field of use of the handling mechanism can be broadened substantially to, for example, remove blanks from a storage area and feed them to the machine and taking the finished parts and removing them from the machine and delivering them to a storage place on, for example, a pallet or a conveying mechanism or the like.
It is also a purpose of the invention to further increase the stiffness of the structure. The double support of the joints and avoiding of so-called cantilevered supports reduces the otherwise existing elasticity in the joints.